(1) Field of the Invention
The present invention relates to a graphic display meter for providing graphical vehicle driving related information, by displaying a dial and a pointer on a display device thereof such as a liquid crystal display (LCD) in the form of a dot matrix. Accordingly, the present invention is particularly suitable for use with an automotive vehicle.
(2) Description of the Related Art
In conventional graphic display meters, in a case where the pointer is driven to rotate rapidly, too many images of the pointer including its after-images are displayed thereon, causing inconvenience to a vehicle user. To solve the above discussed problem, there has been proposed a graphic display meter which is disclosed, for example, in Japanese Patent Application Publication No. 2003-262542. The conventional graphic display meter as suggested is designed such that it can represent a shadow on the opposite side to the side where the pointer is rotating, when the pointer rotates at a speed greater than a predetermined speed.
This type of meter can eliminate a multiplicity of after-images and is adapted to present fast-moving images, when dynamically varying images are made to be displayed. In addition to above discussed technology, both Japanese Patent Application Publication No. 2002-15335 and Japanese Patent Application Publication No. 2003-233828 also disclose a similar technology to the disclosure provided in Japanese Patent Application Publication No. 2003-262542, so called a “motion blur” technology.
In the afore-mentioned graphic display meter, while the pointer is preferably to be displayed by using the motion blur technology in a case where it is made to move at a high rate of speed, otherwise (i.e., when it is either stopped or moving at a decreased speed), it is necessary to display a normal pointer image in order to ensure that the information, which is provided by the pointer, such as actual vehicle speed and engine speed is clearly displayed. For this reason, the motion blur display mode has to be switched to the normal display mode, and vice versa.
As such, the motion blur display mode is used when the pointer moves too fast to be recognizable to a vehicle operator, and has to be switched to the normal display mode when the pointer moves slow enough that the pointer is recognizable to the vehicle operator. However, a difficulty is encountered when the motion blur display mode is switched to the normal display mode. The pointer is still moving at a speed ranging between the stopped state and the afore-mentioned high speed, resulting in a gap in dependence on the moving speed difference of the pointer between the normal display mode and the motion blur display mode.
As a result, at the time of the afore-mentioned mode changes, the vehicle operator recognizes both the motion blur pointer image and the normal pointer image at the same time, and also recognizes a space between the normal pointer image and the motion blur pointer image, which causes inconvenience to the vehicle operator.
In view of the above problems in the conventional arts, the present invention has an object to provide an improved graphic display meter which is prevented from causing inconvenience to the vehicle operator, when the motion blur display mode is switched to the normal display mode.